1. Field of the Invention
The present invention relates to a sheet feeder cassette for holding of sheets to be supplied to such an image forming apparatus as a printer, a plotter, a photocopier or a telecopier.
2. Description of the Related Art
A conventionally-known sheet feeder cassette has a shape of box which stores sheets to be fed. Since this type of sheet feeder cassette has a top plate, an advantage thereof is that the stored sheets are protected from dusts and such which may stick to the surfaces thereof.
Since the image forming apparatus forms images on sheets of various sizes, the sheet feeder cassettes are designed so as to store the sheets of various sizes.
For example, a sheet feeder cassette, which can store sheets of both A3 size that is comparatively large and A4 size that is comparatively small, is formed in a size that is appropriated to A3 which is the larger size and thus, when the smaller sheets of A4 size are stored, a partition plate or the similar which is provided inside the cassette is moved so as to match the A4 size or a partition plate is installed inside the cassette so that the A4-size sheets can be held.
In the sheet feeder cassette described above, since the size of the cassette itself remains in a size which is appropriated to the A3 size even when the A4-size sheets are stored, it occupies a large installation space.
Such a problem as above can be solved by a telescopic structure of the sheet feeder cassette.
However, if the sheet feeder cassette is of a telescopic structure simply with a plurality of sheet supporting bodies to constitute a plurality of stages, thickness of the sheet supporting bodies becomes smaller as the stage is closer to rear end and, as the result, another problem that the quantity of storable sheets becomes the smaller is aroused.